Rackshack expects to have a second datacenter, also in Houston, but on a different segment of the power grid, in the first few days of September, and that [at the time of the posting] it had around 600 servers available to rent in its existing datacenter. 600 servers sounds a lot and more than the entire installed base of many hosting companies, but Rackshack is one of the market leaders in Linux/Apache dedicated servers and has been adding in the region of 1000 new Linux servers per month to its network.
Rackshack maxs out Houston power grid segment
Rackshack have posted to their support forums that their power consumption has hit the limit of the local Houston power grid.